void main() {
  ///
  /// 斐波那契数列
  /// author：LiShixi
  /// since：2022-12-12
  int fib(n) {
    return (n == 0 || n == 1) ? n : fib(n - 1) + fib(n - 2);
  }

  print(fib(7));

  var where = ["abc", "abcde", "asdf", "add", "address"]
      .where((element) => element.contains("dd"));
  // 用分隔符连接匹配到的元素
  print(where.join("-"));
  // 打印匹配到的每个元素
  where.forEach(print);
}
